/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 */

package org.dom4j.util;

/**
 * <p> <code>SimpleSingleton</code> is an implementation of the
 * SingletonStrategy interface used to provide common factory access for the
 * same object instance. This implementation will create a new instance from the
 * class specified and will not create a new one unless it is reset. </p>
 * 
 * @author <a href="mailto:ddlucas@users.sourceforge.net">David Lucas </a>
 * @version $Revision: 1.2 $
 */

public class SimpleSingleton implements SingletonStrategy
{
   private String singletonClassName = null;

   private Object singletonInstance = null;

   public SimpleSingleton()
   {
   }

   public Object instance()
   {
      return singletonInstance;
   }

   public void reset()
   {
      if(singletonClassName != null)
      {
         Class clazz = null;
         try
         {
            clazz =
               Thread.currentThread().getContextClassLoader().loadClass(
                  singletonClassName);
            singletonInstance = clazz.newInstance();
         }
         catch(Exception ignore)
         {
            try
            {
               clazz = Class.forName(singletonClassName);
               singletonInstance = clazz.newInstance();
            }
            catch(Exception ignore2)
            {
            }
         }

      }
   }

   public void setSingletonClassName(String singletonClassName)
   {
      this.singletonClassName = singletonClassName;
      reset();
   }

}

/*
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and
 * notices. Redistributions must also contain a copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * 3. The name "DOM4J" must not be used to endorse or promote products derived
 * from this Software without prior written permission of MetaStuff, Ltd. For
 * written permission, please contact dom4j-info@metastuff.com.
 * 
 * 4. Products derived from this Software may not be called "DOM4J" nor may
 * "DOM4J" appear in their names without prior written permission of MetaStuff,
 * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
 * 
 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
 * 
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 */
